rs397517149

Variant names:

• chr2-39022786-T-G
• rs397517149
• NM_005633.4:c.1642A>C

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PP2 PP3 PM2 PS2 PM1 PS3

This summary comes from the ClinGen Evidence Repository: The c.1642A>C (p.Ser548Arg) variant in SOS1 has been reported as a confirmed de novo occurrence in a patient with clinical features of a RASopathy (PS2_VeryStrong; PMID 17143282). In vitro functional studies provide some evidence that the p.Ser548Arg variant may impact protein function (PS3; PMID 23487764). This variant was absent from large population studies (PM2; ExAC, http://exac.broadinstitute.org). The variant is located in the SOS1 gene, which has been defined by the ClinGen RASopathy Expert Panel as a gene with a low rate of benign missense variants and pathogenic missense variants are common (PP2; PMID:29493581). Furthermore, the variant is in a location that has been defined by the ClinGen RASopathy Expert Panel to be a mutational hotspot or domain of SOS1 (PM1; PMID 29493581). Computational prediction tools and conservation analysis suggest that the p.Ser548Arg variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as pathogenic for RASopathies in an autosomal dominant manner. Rasopathy-specific ACMG/AMP criteria applied (PMID:29493581): PP2, PP3, PM1, PM2, PS3 PS2_VeryStrong. LINK:https://erepo.genome.network/evrepo/ui/classification/CA234977/MONDO:0018997/004

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SOS1 NM_005633.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:14
• Conservation: PhyloP100: 2.24
• Publications: 20 publications found

Genes affected

SOS1 (HGNC:11187): (SOS Ras/Rac guanine nucleotide exchange factor 1) This gene encodes a protein that is a guanine nucleotide exchange factor for RAS proteins, membrane proteins that bind guanine nucleotides and participate in signal transduction pathways. GTP binding activates and GTP hydrolysis inactivates RAS proteins. The product of this gene may regulate RAS proteins by facilitating the exchange of GTP for GDP. Mutations in this gene are associated with gingival fibromatosis 1 and Noonan syndrome type 4. [provided by RefSeq, Jul 2008]

SOS1 Gene-Disease associations (from GenCC):

• Noonan syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Noonan syndrome 4

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, Genomics England PanelApp
• fibromatosis, gingival, 1

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• hereditary gingival fibromatosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cardiofaciocutaneous syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• Costello syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• Noonan syndrome with multiple lentigines

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• Noonan syndrome-like disorder with loose anagen hair

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Specifications for SOS1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PS2: For more information check the summary or visit ClinGen Evidence Repository.
• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PM1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005633.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SOS1	NM_005633.4	MANE Select	c.1642A>C	p.Ser548Arg	missense	Exon 10 of 23	NP_005624.2
	SOS1	NM_001382394.1		c.1621A>C	p.Ser541Arg	missense	Exon 10 of 23	NP_001369323.1
	SOS1	NM_001382395.1		c.1642A>C	p.Ser548Arg	missense	Exon 10 of 22	NP_001369324.1	G5E9C8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SOS1	ENST00000402219.8	TSL:1 MANE Select	c.1642A>C	p.Ser548Arg	missense	Exon 10 of 23	ENSP00000384675.2	Q07889-1
	SOS1	ENST00000395038.6	TSL:5	c.1642A>C	p.Ser548Arg	missense	Exon 10 of 22	ENSP00000378479.2	G5E9C8
	SOS1	ENST00000913801.1		c.1642A>C	p.Ser548Arg	missense	Exon 10 of 22	ENSP00000583860.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461112 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726916

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33454

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111406

Other (OTH) AF: 0.0000166 AC: 1 AN: 60370

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0662318), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000534 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
3	-	-	Noonan syndrome 4 (3)
3	-	-	not provided (3)
2	-	-	Noonan syndrome (2)
2	-	-	Noonan syndrome 1 (2)
1	-	-	Cardiovascular phenotype (1)
1	-	-	Noonan syndrome 4;C4551558:Fibromatosis, gingival, 1 (1)
1	-	-	Noonan syndrome and Noonan-related syndrome (1)
1	-	-	RASopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.70	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		2.2
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.75
Sift	Benign	0.057	T
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.75		Gain of MoRF binding (P = 0.0141)
MVP		0.97
MPC		1.6
ClinPred		0.98	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.84
gMVP		0.83
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs397517149; hg19: chr2-39249927;